1. To fall, descend, or collapse to some lower point or level. The boat was struck with another torpedo, and it sank to the bottom of the sea. They've run out of fuel, but so long as they don't encounter any strong winds, their hot air balloon should sink safely to the ground. I sank to the floor in shock when they told me that Michael had been killed.

2. To appear to move to some lower point or level. We sat watching the stars beginning to appear as the sun sank to the horizon.

3. To move or shift to some lower measurement or degree. The temperatures are supposed to sink to -10 degrees tonight! The power station's output sank to just over 200 megawatts.

4. To engage in some negative action or behavior that one or others believe is below a certain standard of dignity, principles, or integrity. Don't sink to his juvenile taunts. Just ignore him. I can't believe he would sink to spreading lies about me like that. I lost faith in the news site when they sank to posting vacuous, clickbait-driven articles.